Packaging structure



1941. v R. M. BERGSTEIN Re. 21,971

PACKAGING s'rnuc'rimm Original Filed Batch 2, 1936 2 Sheets-Sheet 1INVENTOR. Rosier/V0221: Etna-57:1.

ATTORNEYS.

Reissued Dec. 9, 1941 UNITED STATES PATENT OFFICE mf'fiimm amen ments;original No. 2,170,364, dated August 22, 1939,

Serial No. 66,850, March 1936.

Application for reissue April 23, 1940, Serial No. 331,263

3Cialms.

other aspects in my Letters Patent Nos. 2,154,083,.

granted April 11, 1939; 2,097,427 granted Nov.

\ tents at any point unassisted by the surrounding members of thepackage.'

2, 1937; and 2,099,257 granted November 16, 1937.

This is a reissue of my Letters Patent No. 2,170,364, dated August 22,1939,

In my development of packaging devices and manufacturing methods formaking them, as disclosed in the patents above noted, I have beendirecting my attention to the provision of a package which will to amaximum degree, exclude moisture, liquid, and be gas and air tight when.the product to be packed is installed therein. It

is also directed to the provision of such a package which can be usedeasily in familiar carton-filling or bag-filling machining methods, andwhich is cheap to manufacture, and inexpensive, to use.

One of the main objects in the. development,

- carbon dioxide, and thereafter filling such container with thecontents, thus resulting in a con tainer being filled with the contentsplus an inert gas minus air, the oxygen in which being largelyresponsible for the deterioration of foods. It will be obvious thatcontents thus protected will have a protection similar to that offeredby a vacuumized tin or glass container, at a fraction of the cost ofsuch container.

A part of my said development has been the provision of a bag which ispreferably in'the form of a tube seamed by heatfusion, and preferablythis bag is built into a carton having relatively stiif or rigid walls.Incident to the development is the sealing by heat fusion of the one endof the bag and provision for subsequent sealing by heat fusion of theopen end of the bag. In this way the contents of the package issurrounded by an integral body of material which naturally is asimpermeable to. gas and moisture transmission as is possible. In thisway also, it

'is practical to install in a carton a bag which is at least as largearound as, the enclosing walls of the carton, and preferably fastened tothe carton, thus assuring that the bag itself does not have to sustainthe stress and strain of its con- Among other materials which I employin connection with my packaging development are materials which are veryimpermeable to gas and liquid and moisture penetration and in additionare heat fusible'inand of themselves, without, the necessity of using aheat fusible medium for the seams. Such materials are more impermeablethan any others of a flexible nature and light in weight, which arepractical for use in inexpensive packaging of commodities. Their verygreat advantage in permitting a rapid inexpensive tightly sealed closureis obvious.

Such a material which I, have found very advantageous, is a thin rubbercomposition of which a type is sold under the name Pliofilm. Othermaterials highly impermeable, and thin and heat-fusible are, however,available. There are several difficulties attendant upon the use of suchmaterials arising from the fact that they are flimsy, and must behandled carefully both in building the package and filling and sealingit.

To form an air or liquid tight. bag of such gnu-- terial as Pliofllm" byitself is a difficult operation, since a tiny speck of dust in thebag-making apparatus is likely to puncture it. Also incident to suchmaterial is a rapid softening under heat so thatattempts to seal it byheat fusion are likely to so attenuate the portions being heated as tocause a break or an incipient break in the material.

Accordingly it is one of the objects of the present invention to pro ectthe web of thin heatfusible material during the formation of the bag andthe final closure thereof by a web of heavier material. In this way thefeeding of the bagfonning materials can be facilitated, and theapplication of heat can-be done through the heavier material, thusavoiding any excessive pressure, I

and cushioning any pressure where pressure is used, to prevent crushingor attenuating th heat-fusible material.

It is another object of the invention to provide a bag or packagecontaining a bag, which has has internally thereof a complete integralweb in) Because of its relatively greater cost a .Inthedrawings:

use as an example, is preferably used in its thinnest form. Byintroducing the exterior reinforcing ply of paper it is thereby-possibleto make use of such a material or sheeting in a thinner form than wouldotherwise be practical.

(b) Due to its flexible naturesuch material is extremely susceptible topuncturing or rupturing while it is being drawn through the bag machine,so that the outer reinforcing ply offers protection to the fusible'fllmduring the course of manufacture of bags therefrom.

The application of Heat to a seam formed of such material causes theheated portion to become quite plastic during the time of fusing, in-

creasing its normal susceptibility to puncturing or distortion, and bythe introduction of an exterior reinforcing ply the heat can be appliedthrough the exterior ply, effectively preventing such distortions orpunctures.

(d) I have discovered that in applying heat to fuse such material themere contact of the pertions to be fused alone is all that is requiredand that further pressureisnotnecessary. In factsat-.

isfactory fusion can be effected by retaining contact of overlappededges by guides, so that radiant heat will fuse the edges without theheating element contacting thematerial.

(e) The finished bag can be handled, opened and packed more readily thanwould be possible without the paper reinforcing ply because it possesses the handling qualities of a paper bag infusible material ofhighly resistant nature gas and liquid penetration such as Pliofilm,which I Fig. 1 is a plan'view showing an'arrangement of a heat-fusibleply and backing ply convenient for use in followi g my invention.

Fig. 2 illustrates a mode of forming such a strip as shown in Fig. i,into a tubular structure. Fig. 3 is a section on the line 3 -3 of Fig.2. a

Fig. 4 shows in perspective a bag formed of a section of the tubularstructure, wherein the onev end thereof is sealed by heat fusion bymeans of heat applied to a zone across the end of the bag.

Fig. 5 is a diagram showing the'mode in which the bag may be housed in acarton during the operation of folding and cementing the carton.

Fig. 6 shows in perspective a carton containing the bag and opened forreception of the contents,

with an observation panel left in the outer'ply of I the bag and in thecarton.

In the drawings, a flat piece, or sheet of paper l-has a sheet -2 ofthin flexible heat-fusible materi'al positioned on it so that the edge 3of the paper sheet, extends out laterally from the 'parallel edge 4 ofthe material. At the other side of the sheets the edge 5 of the sheet 2extends out beyond the edge 6 of the paper. Preferably the two webs areunited by a layer of latex (not shown) which acts as an adhesive to jointhem together. Some other cement might be employed although it shouldpreferably be permanently flexible. In some instances bands or spots ofcev ment can be used or none at all.

The two sheets are folded together over a folding plate I. along thelines a-b, 'c-d, and. as

stead of the extreme flimsiness and. pliability which characterize a bagmade of thin heatiusible material alone.

It is very important that an adhesive be used to combine the plys thatwill not harden or become brittle, so that when the bag is opened forfilling or is folded after being filled any such folds will not have atendency tocrack or break the fusible material which would be the caseif the adhesive became'brittle or hardened. I have discovered that byusing a rubber latex adhesiveI secureavery goodbond betweentheplysandbecause the rubber-like adhesive remains permanently pliable, it permitsfolding and handling without injury to the fusible ply. Further, the useof such rubber-like adhesive serves to fill efrectively any slightpinholes or punctures that there might be in the fusible film andfurthermore through the use of this type of adhesive'the resistance togas or liquid penetration is increased considerably beyond that whichthe fusible iilm alone Incidentally any obiectionable odor of theadhesive film is blocked off by the internal ply. g

It should be noted that the bag of my present improvement when housed ina carton in accord- .ance with other aspects of my development, referredto in my applications above identified, will be fully effective. inplace of the bags which I have described in those applications.

I will describe my invention with reference to several examples only,and showing but one form ofbamandintheclaimsthatfollowwillstatethenoveltyinherentinthesaiddisclosine. Iwill not endeavor to re-statematters which are brought outinmysaidissuedpatents, sinceIeonsider theminterdependent with the present features of the development, although insome respectsthereare aspects of the said patents which are notsoimportant inthepreeenteasaasreferencetotheolaimsheretoappended'willshow.

will benoted from the sectional'views, the edge -.4'of the sheet 2'overlaps the opposite edge 5 of the said sheet. The edge! of the paperwill also overlap the opposite edge 8 of the paper sheet. The foldingplate is interposed between opposite walls of the folded material. I

An adhesive is applied along one of the meet ing surfaces of the papersheet as indicated at Fl, or it may be applied to the under-surface ofthe corresponding meeting surface (the mar ginal portion a-h), or themeeting surfaces of the paper sheet may be coated with a rubber latexadhesive which on pressing together, will form a firm overlapping jointresulting in the cohesion'of one edge of the paper cover to its opposededge in a lap seam joint.

It will be noted that the two joints, that is the paper joint and thejoint in the sheet 2 of flexible heat plastic material, are preferablynot in registry and pressure which causes adhesion at I, and which maybe heated by whatever tem-v of the edges of the paper sheet as by aroller ii, is not required to Join the edges of the sheet 2.-

IBhe edges of the sheet 2 may be fused togethe'mi.

in an overlapped joint by bringing the tube into proximity of a heatingunit such as' is indicated perature is required for fusion. With thesheet edges can be caused to fuse-together either by ,contact with theheating unit or by locating the heating unit close to the overlappededges. The folding plate being interposed between the oppoat the seam.

Iflnd that the fusion of the inner sheet without the use of pressure andwithout a heated pressure roller or bar applied directly to the seam Iis preferable as it avoids any tendency to buckle and curl up. The heatalso makes a better lapped j folded flatwise in bag formation theoverlapped 'sitewall, prevents fusing the inner sheet except i seamJoint through the thicknessof one ply of,

paper than would occur were the fusible web be exposed to a direct heat.

' The plural ply tubular section isthen by the application of heat in'aband laterally across the sheet to form a securely fused end seal Jointand the material may be at this point cut into sections, completing thebag. If desired the closed end may be folded over double and securedwith adhesive, as shown in Figure i and in accordance with the methodshown. in

the application of Samuel Bergstein, Serial No.

515,275, flled Feb. 12, 1931, now Patent No. 2,074,886, March'23', 1937.If this is done the heat-sealing, may be a subsequent operation. Doublefolding has the advantage of keeping any strain off of'the sealed end.

Purely hand manipulation in the various steps of the above method willbe readily applicable,

although carrying out of the steps by the use of available automaticmachinery'is of course, the best mode of practice.

A bag machine can be modified to operate very rapidly using the methodabove outlined. The

plural ply tube is formed over a forming plate,

from the two webs of material which may be adhesively secured togetherby a preliminary operation. The usual folding elements will act to formthe doublethickness tube, and supply the adhesive to the outer ply, ormoisten or heat the adhesive if it has been previously applied. Afterthe tube is formed and the outer seam formed, the heat contact elementto provide for fusing the inner seam is traversed by the material.

Thereafter, the tube may be cut to length and its direction of movementchanged from the previous direction of travel and one cut end of thetube caused to pass a heating element to or of substantially the samedimension, wherefore it will overlap slightly the combined face and sidewall on which it is deposited, as illustrated. It will also extendbeyond the walls of the carton as illustrated. at the open end, andmmewhat beyond the juncture of the closing flaps with the walls of thecarton at the closed end. The carton is then folded and cemented aboutthe bag.

The features incident to this mode of operation and the resultingstructure are brought out in my above mentioned patents, but it shouldbe noted that the manufacturing operation is easier because of thestrength and body of my present bag.

I have shown both the bag by itself and the bag in a carton ready forinsertion of contents. It will be understood from my above menbringabout a fusion of the inner ply at that end. As an alternative the tubemay be conveyed in a straight line and have a timed heating elementengage it lightly crosswise, to bring about a fusion along whatwill bethe bottom, and thereafter it may be cut. The fused zone need not bewide and the operation is very rapid even through the outer layer. Theresult in either event is "a tubular bag with its inner surface fusedinto an integral body except at one end.

An alternative method of forming the novel bag is to forma tube of theflexible heat-plastic material over the folding plate and when it isformed bring the paper web up around the plate into overlappingarrangement surrounding the heat-plastic tube, in which instance theseams .in the innerv and outer tubes can be in line with each other. Theadhesive juncture of the two webs together can be accomplished duringthis operation, if desired, and the cementing of the seam in theouterply and the inner ply accomplished in the same manner as alreadydescribed;

The lengthwise seam of the heat-plastic ply may be formed before theouter ply is wrapped around the forming plate, although this is notusually desirable, unless the heat-plastic material is quite thick. Ifind that a better'seal is brought larger around than the interior ofthe carton, 7s

tioned patents that when the bag is filled in either instance, it isready for sealing as by stretching out the exposed mouth, and applyingheat to fuse the walls together. The outer ply of the bag serves hereagain as a protection during the sealing operation and here againpressure by the heated element is avoided.

I have illustrated in Fig. 8, a carton which has a window II cuttherein, and there will be a like window 22 formed in the outer web ofpaper of the bag. This window as shown is narrow but will permit of aview of the contents of the package without weakening it substantially.The cream line in a milk container constructed as has been described canbe viewed through such an opening.

carton blanks, after the manner already indicated.

In comparison with my above mentioned patents, the necessity of avoidingany re-entrant folds in the seam or transverse fusion of the bag is notso important where the inner ply is as readily fusible, as. for example,the Pliofllm material which I have mentioned, particularly where it isunited with the outer ply by means of an intervening film of latex.

While I have pointed out the advantages of the aspect of my developmentdisclosed herein, it may be noted that bag-filled cartons constructedaccording to my preferred arrangement have passed through gruellingtests against both leakage ofwater and milk, and leakage of carbondioxide gas, under severe mishandling without being broken or leaking.

Having thus described -my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A plural ply open-mouthed bag comprising an inner ply of heat-fusiblematerial and an outer ply of other flexible material, said inner plyhaving an interior of integral nature with nature with two of its seamsformed by fusion,

two seams formed by fusion, the lengthwise seam 10 of the inner plybeing an o erlapped fused searn andtheendseamthereofbeingafacetofaosfusion of said inner ply across a zone of said ply. which is faced onboth sides the outer. ply.

secured thereto, and the lengthwise overlapped fused seam of the innerply being faced on but one side with the. outer ply each ply in saidbag.

being seamed longitudinally to itself without the interposition of theother ply.

ROBERT MORRIS BERGB'I'EIN.

